Deep decarbonization pathways in the building sector: China's NDC and the Paris agreement

China's economic growth has been largely relying on the consumption of coal. The country has realized that its economic development has to be free from dependence on fossil fuels. On 30 June 2015, China submitted its 'Nationally Determined Contribution (NDC)' in preparation for the Conference of Parties 21 (COP21). One of the important actions in China's NDC is to lower carbon dioxide (CO2) emissions per unit of GDP by 60% to 65% from 2005 levels by 2030. This study examines the efforts from China's building sector (i.e. urban residential, rural residential and service) in achieving the CO2 reduction target stated in China's NDC. Furthermore, this study also explores the post-NDC era and looks into the opportunities towards deep decarbonization in the building sector by mid-century for contributing to the Paris agreement. The study covers 31 provincial regions of mainland China anddisparities of climate and socioeconomic indicators across regions are fully considered. We use a bottom-up cost optimization model called AIM/Enduse to evaluate the CO2 reduction potential brought by efficient technologies in China's building sector. Five scenarios are designed to illustrate the emission pathways through 2050. The results show that, when energy constraint and emission target is introduced in mitigation scenarios, new generation biomass contribute a lot to emission reduction. Reduction potential in the nearly zero emission scenario is mainly from the urban residential sector, and to achieve deep decarbonization by 2050, it is important to bring a significant reduction of per-capita energy consumption in addition to ci improvement both in urban and rural households. Co-benefit analysis suggests that air pollutants can also be significantly reduced by deep decarbonization policies.